Mill



March 16 1926.'

F. SILVA MILL Filed Nov. 21, 1925- 3 Sheets-Sheet l N AR. f bm, F ,So .NW MM. bm. 7

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A MILL Filed Nov. 21, 1925 3 Sheets-,Sheet 2 WIM\ F. SILVA March 16 1926.

MILL

Filed Nov. 21, i925 3 Sheets-Sheet 3 Patented Mar. 16, 1926.

UTE, STATES FRANK SILVA, OF COPPERHILL, TENNESSEE.

MILL.

Application led November 21, 1925. Serial No. 70,594.

To all whom t may concern Be it known that I, FRANK SILVA, fa citizen of the United States, residing at Copperhill, in the county of Polk and State of Tennessee9 have invented certain new and useful lmprovements in Mills, of which the followingis a specification` reference being had to the accompanying drawings.

This invention relates to mills and more particularly to the type of mill employed for reducing rock, ores and the like and employing rollers for the purpose of such reduction. i

An importantobject of the invention is to provide a mill employing internal classification of the materials being reduced and removing from the mill such portions of the materials as have been reduced to the desired size.

A further object ofthe 'invention is to provide a mill having means whereby this internal classification may be accomplished during operation of the mill.

A still further' object 0f the invention is to 'provide a mill, the construction of which embodies the combined advantages of the ball or pebble type mill with that of the roll type mill and in this combination reducing the amount of'power necessary to operate the mill and eliminating the necessity for returning to the mill after discharge therefrom such portions of the materials as have not been properly ground thus adapting the roll type mill for use in the liner grinding operation ordinarily performed by the ball or pebble type mill.

A further and more specific object of the invention is to provide a mill employing wet classification for internal separation of the coarse particles from the finer particles and for removing these liner particles from the mill. Y

These and other objects I attain by the construction shown in `the accompanying drawings, wherein for the purpose of illustration is shown a' preferred embodiment of my invention and wherein Figure 1 is a side elevation of 'a mill constructioned in accordance with my invention; j

Figure 2 is a sectional view showing one of the supports and the shaft mounting;

Figure 3 is a horizontal sectional view through the mill;

Fieles ea enlarge@ detail @eetlepel view showing the manner of applying the ring liner to the mill;

Figure 5 isa vertical sectional view illustrating the operation of the interior of the mill;

-frusto-conical flange 11 forming one side wall of the mill and providing a central axial opening 12 forming the intake of the mill. To the opposite side of the casing 10 is secured a frustro-conical flange 18 forming the opposite side wall of the mill and an axial discharge opening 142 of slightly greater' diameter than the intake opening 12.

The flanges 11 and 12 have secured thereto annular tracks 15 and 16 of thesame external diameter and coaxial with the casing. These tracks rest upon supporting and guiding rollers 17 permitting rotation of the casing but preventing downward movement thereof. As a means of attaching the tracks 15 and 16, the smaller end of the flange 11 is providedl with an inturned attaching flange 18 to which the track 15 Vis secured while the flange 13 is formed in two sections 3a, 13b having at their adjacentv edges flanges 19 between which a web 2O formed Vupon the track 16 is engaged and secured.

'Ihe'casing section 10 is likewise formed in two sections bolted together upon the web 21 of a gear 22 which is preferably of the herring-bone, as illustrated. This gear is engaged by a suitably driven pinion 23 serving as a means for rotating the casing. A ring liner 24 is provided for the central casing section 10, this liner being-secured in position by opposed web blocks 25 connected by bolts 26 as a means for drawing them toward one another, these web blocks coacting with the tapered-faces 27 formed upon the outer surface of the ring liner. Suitable linings 28 and 29 are bolted or otherwise secured, as at 30, upon the interior of the flanges 11 and 13 to protect the same.

Arranged in opposition to'the 'discharge and intake ends ofthe completed casing are suitable supports 31 upon the upper ends of which are mounted inverted U-shaped guide yokes 32. Each guide yoke has slidebly mounted. thersa e Peil 0f UPP-ef @mdr lower blocks 33 and 34, the upper block beingengaged by adjusting screws 35 extending' through the bight of the U-shaped tlf-:mme member and heavy coil springs 36 bein@` arranged upon the blocks. Thus means are provided for yieldably forcing the lower block 34 downwardly. The blocks 34 rcceive the ends of parallel members 3T which Xtend through the intake and discharge openings of the casing and are provided interiorly of the casing` with spaced yoke frames 38 each having at each end thereof a dependingarm 39. Between the lower ends of adjacent arms are mounted crushing rollers 40, which, bythe tension of the springs 36, are forced into engagement with the ring liner 24. By their mounting, the adjacent. faces of these rollers are separated from one another to provide a space 4l, the purpose of which will hereinafter appear.

The yoles at their .upper vsurfaces vform a inouuti-ngl Vfor* an internal feed launder 42. This launder inclines from end to end, the lower end of thelaunder beingl arranged above the roller 40 beneath which a given portion ol the ring liner 24 first passes during rotation of the mill. Adjacent the upper end of this lau'nder, a spray pipe 43 is disposed directing a spray of Water into the upper end of the launder to cause the contents thereof to be Washed from the discharge end and to pass between the roller 40 and the ring liner. A#above the roller 40, a second spray pipe 44 is arranged, this spray pipe direct-ing a spray of Water downwardly and outwardly toward the surface of the ring liner 24 so that the direction of this spray is partially in opposition to the direction of rotation of the ring liner and casing. The direction of rotation of the vcasing is indicated by the arroiv on Figure 5.

The bars 37 at each end of the casing provide monnting's for end plates 45, 46 closing or substantially closing` the intake and discharge openings l2 and 14 respectively. The' plate 45 is formed in upper-and' lower sections 45, 45", hingedly coimected to one another, as at 47. Means are provided, as at 4S, for looking the plates in alignment With one another, such means being removable to permit the upper section 45 toy be swung do'wnivardly, permitting access vtoY the mill. The loujer section 45" is' rigidly secured to the bars 37. The upper section 45 has formed thereinaiii opening?)` '49for the passage of a feed launder and a Water pipe 51 which,y interiorly of the mill, is 'branched to produce the spray pipes 43 and 44. The plate 46 is similarly constructed from the upper and lower sections 46a, 46b hingedly connected, as at '52, and having removable means, as at 53, for holding the sections in aligned relation. The lower section 43"V is rigidly seeured t0 thefibars :37 and has a portion of its lower edge cut away, as atl 54, to provide au opening;` for discharge of liquid and suspended reduced material from he casing. Beneath this opening, a discharge launder 55 is arranged exteriorly of the casing.

ln the operation of the mill above describeth'assuming the mill to be rotating in the direct-ion of the arrow on Figure 5 and material being` fed through the mill feed launder 50, this material, upon reaching the launder 42, is washed down the launder and passes successively between the rollers 40 and 40a and the Walls of the ring liner 22. The crushing pressure of these rollers, will. of course, reduce a certain portion of the material thus fed to the desired size and this reduced material will be more or less in the suspension of the liquid fed intov the mill. At the relatively quiet space provided be tween rthe rollers 40 and 40a, the heavier particles are permitted to precipitate so that they lie against the ringliner While the lighter particles Will pass out With the overi'ioiv at the discharge opening 54 and so to the discharge launder. Of course, a cerain portion of this finer reduced material will cling: to the heavier particles and be carried thereby betiveen the rollers 40a and the liner. This causes a further reduction of the heavier particles and this reduced material is met by the spray 44 which Washes the lighter particles permitting' them `to return to the space 4l and pass to the discharge opening. The heavier particles will, by centrifugalforce, pass the spray 44 and moving upwardly with the casing' will only leave the same when this force is expended. The speedof rotation of the mill 'is such that this takes place at a point 'Where the heavier particles fall upon the upper end of the launder 42, as illustrated in Figure 5 and are' Washed down with the ineoniing feed to pass between' the roller 40 and the liner: It' will be obviousvthat the pressure' placed against the material may be regulated by regulation of the feed screws and that this regulation greater force may be exerted Vagainst the roller 40 or 40th is faune desirable.' Since a Substantial- 'ly uniform pressure is maintained by the rollers against the casingify to urge them' into engagement with` their trackways, the operation of th'o mill is sinoi'ith and the 'fluo t-'uation's a'n'd'poiver demai'id are much. small'- ler thanv those 'ordinarily occurring in the usualtype of mill used' for the vfiner grindina ol'reratio'n".A y

vThe structure herei'nbeforo set forth is obviously capable of a certain range of change and modification and I, therefore, do not limit myself lto such specic structure except as hereinafter claimed.

l. In a mill, a I easingv having 'external traClnvays; rollers engaging said casilngr and supporting the casing for rotation, means for rotating the casing, the casing having at its opposite ends feed and discharge openings, spaced supports projecting through the feed and discharge openings, means 'for yieldably forcing the supports downwardly. crushing rollers carried by the supports within the casingl and means for maintaining a constant fluid level Within the casing. y

ln ai mill, a casing, means for rotating the casing', the casing having at its opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollers carried by the supports within the casing and engaging the interior of the casing at points spaced at cpposite sides of the bottom center of the cas ing and fluid means for classifying the contents of the casing within the casing.

8. In a mill, a casing, means for rotating 'the casing, the casing having at its opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollers carried Vby the supports within the casing and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing and a launder carried by the supports and inclined to deliver material loetvveen the inner Wall of the casing and the roller which is in advance as regards the direction of rotation of the casing and means for maintaining a constant fluid level Within the casing.

4. In `a mill, a casing, the casing having at its opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollers carried by the supports Within the casing and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to deliver material between the inner Wall of thecasing and the roller which is in advance as regards the direction of rotation of the casing and means for rotating the vmill at a speed such that unreduced material Will be deposited in the upper end of said launder by gravity.

5. l'n a mill, a casing, the casing having at its opposite ends feed and discharge openings, supportsy projecting through the feed and discharge openings, crushing rollers arried by the supports within the casing and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to deliver ma-V terial between the inner Wall of the casing and the roller which is in advance as regards the direction of rotation of the casing, means for rotating the mill at a speed such that unreduel material l?? flposited in the upper end of said launder by gravity and means for maintaining a constant fluid level in the casing.

G. In a mill, a casing, the casing having at the opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollH ers carried by the supports Within the cas# ing and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to deliver. material between the inner Wall of the casing and the roller which is in advance as regards the direction of rotation of the casing, means for rotating the mill at a speed such that unreduced material vvill be deposited in the upper end of said launder by gravity and means for spraying said material after its iassage beneath the last named roller to v thereby separate therefrom material Which has been reduced.

7. in a mill, a casing, t'iiecasing having at its Opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollers carried by the supports Within the casing and engaging the. interior of the casing` at points spaced at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to'deliver material between the inner Wall of the casing and thefroller which is in advance as regards the direction of rotation of the casing, means for rotating the mill at a speed such that unreduced material will be deposited in the upper end of said launder by gravity, means for maintaining a constant fluid level in the` casing and means for delivering a spray against the material after its passage beneath the other of said rollers at a point -above the fluid level in the casing and in a direction opposite to the direction of travel of the material.

8. in a mill, a casing, the casing having at its opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollers carried by the supports within the casing and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to deliver material between the inner Wall of the cas ing and the roller which is in advance as rc gards the direction of rotation of the casing, means for rotating the mill at a speed such that unreduced material will be deposited in the upper end of said launder by gravity, and means for delivering a spray to the upper end of the launder to Wash the material from the lower end thereof.

9. In a mill, a casing, means for rotating` the casing, the casing having at its opposite ends feedand discharge openings, supports projecting through the feed and discharge openings, crushing rollers Acarried by the supports Within the casing and engaging the interior of the casing at points spacedv at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to deliver material'between the inner Wall of thel casing and the roller which is in advance as regards the direction of rot-ation of the casing, and means for maintaining a constantly augmented body of fluid Within the casing whereby to provide wet classification of the contents of the casing and to Withdraw lighter particles of the materials from the discharge opening thereof.

10. In' a mill, a casing, means for rotating the casing, the casing havingat its opposite ends feed and discharge openings, supports 'ng through the feed and discharge opennnf crushing rolierscarried byA the supports Within the casing and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing and means for feeding material into the casing between the inner Wall of the casing and the roller which is in advance as regards the direction of rotation of the easing receiving unreduced material after its passage beneath the other of the rollers and delivering' it to the first named roller.

l1. In a mill, a casing means for rotating the casing the casing having at its opposite ends feed and discharge openings,.sup

navigare ports projecting through the feed and discharge openings, crushing rollers carried the supports Within the casing' and engaging the interior of the casing at points spaced at opposite sides of the bottom center of the casing, a launder carried by the supports and inclined to deliver material between the inner Wall of the casing` and the roller which is in advance as regards the direction of rotation of the casing and fiuid means for classifying the contents of the casing' during` rotation of the casing.

12. In a mill, a casing, the casing` having at its opposite ends feed and discharge openings, supports projecting through the feed and discharge openings, crushing rollers carried by the supports within the easing and engaging the interior of the casing atpoints spaced at opposite .sides of the bottoincenter of the easing, a launder carried by the supports and inclined to deliver material between theinner wall of the casing and the roller which is in advance as regards the direction of rotation of the casing, meansv for rotating 'the mill at a speed such that unreduced material will be deposited in the upper end of said leander by gravity and means for classifying the contents ofv the casing duringrotation of the casing.

In testimony whereof I hereunto aflif; my signature.

FRANK SILVA. 

